【摘要】 稀土烧绿石材料（R₂B₂O₇）是一种典型的三维自旋阻挫体系材料，具有一些奇特的基态性质，包括经典自旋冰、量子自旋冰等.其中R代表不同的稀土磁性离子，B₂代表两个过渡金属离子，且可以是两种不同价态的离子，如Ga³⁺Sb⁵⁺,这种由不同过渡金属离子混合形成的烧绿石化合物，会对体系基态性质产生较大影响.本工作利用助熔剂法制备出Yb₂AlSbO₇单晶样品，并测量其低温磁性与比热性质.XRD结果表明其结构为烧绿石结构，其中Al³⁺和Sb⁵⁺离子随机占据同一位置从而在体系内引入无序.磁性与比热结果表明Yb₂AlSbO₇在低温表现出反铁磁相互作用，但直至0.4 K都没有磁转变.磁比热在0.5 K以下与温度成线性关系，与自旋玻璃在低温比热上出现的行为类似，无序可能导致Yb₂AlSbO₇在低温下发生了自旋冻结.更多还原

【Abstract】 Rare earth pyrochlore（R₂B₂O₇） is a typical 3D spin frustrate system material, which has some peculiar ground state properties, including classical spin ice and quantum spin ice. R represents different rare earth magnetic ions, B₂ represents two different valence transition metal ions, such as Ga³⁺Sb⁵⁺. This pyrochlore compound formed by the mixture of different transition metal ions will have a greater impact on the ground state properties. In this work, we grow the Yb₂AlSbO₇ single crystals by flux method and measure the low temperature magnetism and specific heat. XRD results confirm the pyrochlore structure, in which Al³⁺ and Sb⁵⁺ ions occupy the same position randomly and introduce disorder in the system. The magnetic susceptibility and specific heat data show that Yb₂AlSbO₇ exhibits antiferromagnetic interaction at low temperature, but it does not show magnetic transition at low temperature down to 0.4 K. There is a linear relationship between temperature and magnetic specific heat below 0.5 K,similar to the behavior of spin glass at low temperature specific heat, indicating that the disorder may lead to spin freezing of Yb₂AlSbO₇ at low temperature.更多还原